[
https://issues.apache.org/jira/browse/FLINK-25593?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jing Zhang updated FLINK-25593:
-------------------------------
Description:
A redundant scan could be skipped if it is an input of join and the other input
is empty after partition prune.
For example:
ltable has two partitions: pt=0 ad pt=1, rtable has one partition pt1=0.
The schema of ltable is (lkey string, value int).
The schema of rtable is (rkey string, value int).
{code:sql}
SELECT * FROM ltable, rtable WHERE pt=2 and pt1=0 and `lkey`=rkey
{code}
The plan is as following.
{code:java}
Calc(select=[lkey, value, CAST(2 AS INTEGER) AS pt, rkey, value1, CAST(0 AS
INTEGER) AS pt1])
+- HashJoin(joinType=[InnerJoin], where=[=(lkey, rkey)], select=[lkey, value,
rkey, value1], build=[right])
:- Exchange(distribution=[hash[lkey]])
: +- TableSourceScan(table=[[hive, source_db, ltable, partitions=[],
project=[lkey, value]]], fields=[lkey, value])
+- Exchange(distribution=[hash[rkey]])
+- TableSourceScan(table=[[hive, source_db, rtable, partitions=[{pt1=0}],
project=[rkey, value1]]], fields=[rkey, value1])
{code}
There is no need to scan right side because the left input of join has 0
partitions after partition prune.
was:
A redundant scan could be skipped if it is an input of join and the other input
is empty after partition prune.
For example:
ltable has two partitions: pt=0 ad pt=1, rtable has one partition pt1=0.
The schema of ltable is (lkey string, value int).
The schema of rtable is (rkey string, value int).
{code:java}
SELECT * FROM ltable, rtable WHERE pt=2 and pt1=0 and `lkey`=rkey
{code}
The plan is as following.
{code:java}
Calc(select=[lkey, value, CAST(2 AS INTEGER) AS pt, rkey, value1, CAST(0 AS
INTEGER) AS pt1])
+- HashJoin(joinType=[InnerJoin], where=[=(lkey, rkey)], select=[lkey, value,
rkey, value1], build=[right])
:- Exchange(distribution=[hash[lkey]])
: +- TableSourceScan(table=[[hive, source_db, ltable, partitions=[],
project=[lkey, value]]], fields=[lkey, value])
+- Exchange(distribution=[hash[rkey]])
+- TableSourceScan(table=[[hive, source_db, rtable, partitions=[{pt1=0}],
project=[rkey, value1]]], fields=[rkey, value1])
{code}
There is no need to scan right side because the left input of join has 0
partitions after partition prune.
> A redundant scan could be skipped if it is an input of join and the other
> input is empty after partition prune
> --------------------------------------------------------------------------------------------------------------
>
> Key: FLINK-25593
> URL: https://issues.apache.org/jira/browse/FLINK-25593
> Project: Flink
> Issue Type: Sub-task
> Components: Table SQL / Planner
> Reporter: Jing Zhang
> Priority: Major
>
> A redundant scan could be skipped if it is an input of join and the other
> input is empty after partition prune.
> For example:
> ltable has two partitions: pt=0 ad pt=1, rtable has one partition pt1=0.
> The schema of ltable is (lkey string, value int).
> The schema of rtable is (rkey string, value int).
> {code:sql}
> SELECT * FROM ltable, rtable WHERE pt=2 and pt1=0 and `lkey`=rkey
> {code}
> The plan is as following.
> {code:java}
> Calc(select=[lkey, value, CAST(2 AS INTEGER) AS pt, rkey, value1, CAST(0 AS
> INTEGER) AS pt1])
> +- HashJoin(joinType=[InnerJoin], where=[=(lkey, rkey)], select=[lkey, value,
> rkey, value1], build=[right])
> :- Exchange(distribution=[hash[lkey]])
> : +- TableSourceScan(table=[[hive, source_db, ltable, partitions=[],
> project=[lkey, value]]], fields=[lkey, value])
> +- Exchange(distribution=[hash[rkey]])
> +- TableSourceScan(table=[[hive, source_db, rtable,
> partitions=[{pt1=0}], project=[rkey, value1]]], fields=[rkey, value1])
> {code}
> There is no need to scan right side because the left input of join has 0
> partitions after partition prune.
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
